An all-in-one nanoprinting approach for the synthesis of a nanofilm library for unclonable anti-counterfeiting applications

In addition to causing trillion-dollar economic losses every year, counterfeiting threatens human health, social equity and national security. Current materials for anti-counterfeiting labelling typically contain toxic inorganic quantum dots and the techniques to produce unclonable patterns require tedious fabrication or complex readout methods. Here we present a nanoprinting-assisted flash synthesis approach that generates fluorescent nanofilms with physical unclonable function micropatterns in milliseconds. This all-in-one approach yields quenching-resistant carbon dots in solid films, directly from simple monosaccharides. Moreover, we establish a nanofilm library comprising 1,920 experiments, offering conditions for various optical properties and microstructures. We produce 100 individual physical unclonable function patterns exhibiting near-ideal bit uniformity (0.492 ± 0.018), high uniqueness (0.498 ± 0.021) and excellent reliability (>93%). These unclonable patterns can be quickly and independently read out by fluorescence and topography scanning, greatly improving their security. An open-source deep-learning model guarantees precise authentication, even if patterns are challenged with different resolutions or devices

Nanolayer Laser Absorber for Femtoliter Chemistry in Polymer Reactors

Laser-induced forward transfer (LIFT) has the potential to be an alternative approach to atomic force microscopy based scanning probe lithography techniques, which have limitations in high-speed and large-scale patterning. However, traditional donor slides limit the resolution and chemical flexibility of LIFT. Here, a hematite nanolayer absorber for donor slides to achieve high-resolution transfers down to sub-femtoliters is proposed. Being wettable by both aqueous and organic solvents, this new donor significantly increases the chemical scope for the LIFT process. For parallel amino acid coupling reactions, the patterning resolution can now be increased more than five times (>111 000 spots cm−2 for hematite donor vs 20 000 spots cm−2 for standard polyimide donor) with even faster scanning (2 vs 6 ms per spot). Due to the increased chemical flexibility, other types of reactions inside ultrasmall polymer reactors: copper (I) catalyzed click chemistry and laser-driven oxidation of a tetrahydroisoquinoline derivative, suggesting the potential of LIFT for both deposition of chemicals, and laser-driven photochemical synthesis in femtoliters within milliseconds can be explored. Since the hematite shows no damage after typical laser transfer, donors can be regenerated by heat treatment. These findings will transform the LIFT process into an automatable, precise, and highly efficient technology for high-throughput femtoliter chemistry

Spherulitic Crystal Growth Drives Mineral Deposition Patterns in Collagen-Based Materials

The formation of the hard tissues that provide support and mobility to organisms is achieved through the interplay of inorganic crystals and an organic framework composed of collagen and a small percentage of non-collagenous proteins. Despite their clinical relevance, the mechanisms governing mineralization of the extracellular matrix are still poorly understood. By using 3D electron tomography and high-resolution electron microscopy imaging and spectroscopy, it has been demonstrated that mineralization proceeds through a spherulitic-like crystal growth process. First, aggregates of disordered crystals form in the interfibrillar spaces, which lead to the mineralization of adjacent fibrils. Mineral propagates steadily through the inter- and intrafibrillar spaces of the collagen structure forming layered spherulites that grow to confluence. The structure of the collagen fibrils serves as a protein scaffold to guide the formation of a myriad of platelet-shaped crystallites that make up each of these spherulites. At their periphery, nanosized unmineralized areas remain, leading to the formation of the characteristic lacy pattern observed in the transversal cross-section of mature calcified tissues. This study provides fundamental insights into the bone formation process and represents a potential strategy for complex materials designProjekt DEA

An all-in-one nanoprinting approach for the synthesis of a nanofilm library for unclonable anti-counterfeiting applications

In addition to causing trillion-dollar economic losses every year, counterfeiting threatens human health, social equity and national security. Current materials for anti-counterfeiting labelling typically contain toxic inorganic quantum dots and the techniques to produce unclonable patterns require tedious fabrication or complex readout methods. Here we present a nanoprinting-assisted flash synthesis approach that generates fluorescent nanofilms with physical unclonable function micropatterns in milliseconds. This all-in-one approach yields quenching-resistant carbon dots in solid films, directly from simple monosaccharides. Moreover, we establish a nanofilm library comprising 1,920 experiments, offering conditions for various optical properties and microstructures. We produce 100 individual physical unclonable function patterns exhibiting near-ideal bit uniformity (0.492 ± 0.018), high uniqueness (0.498 ± 0.021) and excellent reliability (>93%). These unclonable patterns can be quickly and independently read out by fluorescence and topography scanning, greatly improving their security. An open-source deep-learning model guarantees precise authentication, even if patterns are challenged with different resolutions or devices

Micro‐blooming: hierarchically porous nitrogen‐doped carbon flowers derived from metal‐organic mesocrystals

Synthesis of 3D flower‐like zinc‐nitrilotriacetic acid (ZnNTA) mesocrystals and their conformal transformation to hierarchically porous N‐doped carbon superstructures is reported. During the solvothermal reaction, 2D nanosheet primary building blocks undergo oriented attachment and mesoscale assembly forming stacked layers. The secondary nucleation and growth preferentially occurs at the edges and defects of the layers, leading to formation of 3D flower‐like mesocrystals comprised of interconnected 2D micropetals. By simply varying the pyrolysis temperature (550–1000 °C) and the removal method of in the situ‐generated Zn species, nonporous parent mesocrystals are transformed to hierarchically porous carbon flowers with controllable surface area (970–1605 m2 g−1), nitrogen content (3.4–14.1 at%), pore volume (0.95–2.19 cm3 g−1), as well as pore diameter and structures. The carbon flowers prepared at 550 °C show high CO2/N2 selectivity due to the high nitrogen content and the large fraction of (ultra)micropores, which can greatly increase the CO2 affinity. The results show that the physicochemical properties of carbons are highly dependent on the thermal transformation and associated pore formation process, rather than directly inherited from parent precursors. The present strategy demonstrates metal‐organic mesocrystals as a facile and versatile means toward 3D hierarchical carbon superstructures that are attractive for a number of potential applications

Cobalt‐Exchanged Poly(Heptazine Imides) as Transition Metal–Nx Electrocatalysts for the Oxygen Evolution Reaction

Poly(heptazine imides) hosting cobalt ions as countercations are presented as promising electrocatalysts for the oxygen evolution reaction (OER). A facile mixed‐salt melt‐assisted condensation is developed to prepare such cobalt poly(heptazine imides) (PHI‐Co). The Co ions can be introduced in well‐controlled amounts using this method, and are shown to be atomically dispersed within the imide‐linked heptazine matrix. When applied to electrocatalytic OER, PHI‐Co shows a remarkable activity with an overpotential of 324 mV and Tafel slope of 44 mV dec−1 in 1 m KOH.DFG, 390540038, EXC 2008: UniSysCatTU Berlin, Open-Access-Mittel - 202

Elastin-Like Protein, with Statherin Derived Peptide, Controls Fluorapatite Formation and Morphology

Life Science Initiative, QMUL. The work was additionally supported by the European Research Council Starting Grant (STROFUNSCAFF) and the Marie Curie Career Integration Grant (BIOMORPH). The authors would like to acknowledge Dr. Carol Crean and Dr. Rachida Bance-Soualhi (Department of Chemistry, University of Surrey) for their help with acquiring the Raman spectroscopy data, funded by EPSRC (grant number EP/M022749/1). KS gratefully acknowledges Dr. Sherif El-Sharkawy for intellectual input and Gastón Agustín Primo for help with FTIR deconvolution, alongside other group members of the Mata, MHAtriCell and DPSU groups